Overview of the potent cyanobacterial neurotoxin β-methylamino-L-alanine (BMAA) and its analytical determination

Blue-green algae are responsible for the production of different types of toxins which can be neurotoxic, hepatotoxic, cytotoxic and dermatotoxic and that can affect both aquatic and terrestrial life. Since its discovery the neurotoxin β-methylamino-L-alanine (BMAA) has been a cause for concern, being associated with the neurodegenerative disease amyotrophic lateral sclerosis/Parkinsonism–dementia complex (ALS/PDC). The initial focus was on Guam where it was observed that a high number of people were affected by the ALS/PDC complex. Subsequently, researchers were surprised to find levels of BMAA in post mortem brains from Canadian patients who also suffered from ALS/PDC. Recent research demonstrates that BMAA has been found at different levels in the aquatic food web in the brackish waters of the Baltic Sea. There is emerging evidence to suggest that sand-borne algae from Qatar can also contain BMAA. Furthermore, there is now concern because BMAA has been found not only in warmer regions of the world but also in temperate regions like Europe. The aim of this review is to focus on the methods of extraction and analysis of the neurotoxic non-protein amino acid BMAA. We also consider the neurotoxicity, aetiology, and diverse sources and routes of exposure to BMAA. In recent years, different methods have been developed for the analysis of BMAA. Some of these use HPLC-FD, UPLC-UV, UPLC-MS and LC-MS/MS using samples that have been derivatised or underivatised. To date the LC-MS/MS approach is the most widely used analytical technique as it is the most selective and sensitive method for BMAA determination.     

Iodine Value and Fatty Acids Determination on Pig Fat Samples by FT-NIR Spectroscopy: Benefits of Variable Selection in the Perspective of Industrial Applications

In this work, FT-NIR spectroscopy was employed to determine iodine value (IV) and fatty acids (FA) content of pig fat samples, through the combined use of signal preprocessing, multivariate calibration, and variable selection methods. In particular, the main focus was on the use of variable selection methods, both in order to improve the predictive performance of the calibration models, and to identify relevant wavelengths that could be subsequently used for the development of simple, fast, and cheap hand-held devices, able to measure IV and FA content directly on the fat without the need of any sample pretreatment. Firstly, for each property of interest, partial least squares (PLS) multivariate calibration models were calculated considering the whole spectral range and testing different signal preprocessing methods. Then, once chosen the optimal signal preprocessing method, a two-step variable selection procedure was applied. In the first step, the interval-PLS variable selection algorithm was used to calculate a set of calibration models, whose outcomes were considered altogether in the second step, in order to select the optimal calibration model. The variable selection procedure allowed to lower the number of spectral variables retained by the model, and often led to an increase of the performance in prediction of the external test set samples.     

Fatty acid profiles in meat from Caiman yacare (Caiman crocodilus yacare) raised in the wild or in captivity

Chemical composition and fatty acid profiles were determined in Caiman yacare meat originating from the neck and tail cuts of animals raised in the wild (n = 6) or in captivity (n = 6), slaughtered at a live weight of approximately 6 kg. All experimental methods were approved by the appropriate environmental protection agencies. Most chemical components were affected by the origin-cut interaction, with the tail cut of wild animals having the highest amount of intramuscular fat (19.2% of DM) and the lowest of moisture (71.8%) and protein (77.0% of DM). Yacare meat had low amounts of SFA (35.1%), which were similar (P > 0.05) in the cuts and origins studied. The total amount of PUFA was higher (P < 0.05) in wild (31.0%) than in captive animals (23.6%), and n − 3 fatty acids had means of about 5% and 2% for the same groups, respectively (P < 0.05). In general, the FA profile of intramuscular fat in yacare meat had a desirable PUFA/SFA ratio above 0.4.     

Effect of high pressure processing on wheat dough and bread characteristics

Microbial, physical and structural changes in high pressured wheat dough were studied as a function of pressure level (50-250 MPa) and holding time (1-4 min). Thereafter, selected conditions of high hydrostatic processing (HPP) were applied to bread dough and the technological quality of the obtained breads was studied. The effect of HPP on wheat dough was investigated by determining microbial population (total aerobic mesophilic bacteria, moulds and yeasts), color and mechanical and texture surface related dough parameters (cohesiveness, adhesiveness, hardness and stickiness). HPP reduced the endogenous microbial population of wheat dough from 10⁴ colony forming units/g (CFU) to levels of 10² CFU. HPP treatment significantly (P < 0.05) increased dough hardness and adhesiveness, whereas treatment time reduced its stickiness. Scanning electron micrographs suggested that proteins were affected when subjected to pressure levels higher than 50 MPa, but starch modification required higher pressure levels. HPP treated yeasted doughs led to wheat breads with different appearance and technological characteristics; crumb acquired brownish color and heterogeneous cell gas distribution with increased hardness due to new crumb structure. This study suggests that high hydrostatic processing in the range 50-200 MPa could be an alternative technique for obtaining novel textured cereal based products.     

Relative effect of particle size on the physical properties of corn meal extrudates: Effect of particle size on the extrusion of corn meal

Corn meal of various particle sizes ranging from 180 to 710 μm were processed in a twin-screw extruder to produce directly expanded extrudates. The extrusion process effects on the specific mechanical energy (SME), expansion indexes (radial, longitudinal and volumetric), pasting viscosity, water absorption index (WAI) texture properties, and microstructure were determined. Increasing the particle size decreased the SME input. Extrudates produced with corn meal of higher particle sizes expanded more than extrudates produced with smaller particle sizes. For all treatments there was no peak viscosity at 95 °C. But expanded corn meal extrudate from the 180 μm fraction showed a discontinuous gel matrix phase. Increasing corn meal particle size decreased WAI values. The mechanical resistance of the extrudates from the smallest particle size was significantly higher (p < 0.05) than that of the largest particle size. The microstructure of raw corn meal revealed large fractured particles with small rounded particles adhering to the surface.     

Time dependence of bioactive compounds and antioxidant capacity during germination of different cultivars of broccoli and radish seeds

Optimisation of the germination process of different cultivars of broccoli (Brassica oleracea var. italica cv. Lucky, cv. Tiburon and cv. Belstar) and radish (Raphanus sativus cv. Rebel and cv. Bolide) seeds in relation to the content of glucosinolates (GLS), vitamin C and total antioxidant capacity was carried out in order to maximise the health-promoting properties of Brassica sprouts. The content of total and individual GLS varied between species, among cultivars, and germination time. Glucoraphanin in broccoli and glucoraphenin in radish were the predominant GLS in raw seeds (61–77 and 63–129 μmol/g DM, respectively) and, although their content decreased during germination, they were maintained in rather large proportions in sprouts. Vitamin C was not detected in raw seeds and its content increased sharply in broccoli and radish sprouts (162–350 and 84–113 mg/100 g DM, respectively). Raw brassica seeds are an excellent source of antioxidant capacity (64–90 and 103–162 μmol Trolox/g DM in broccoli and radish, respectively) and germination led to a sharp increase. Germination of broccoli cv. Belstar and radish cv. Rebel for 4 days provided the largest glucoraphanin and glucoraphenin content, respectively, and also brought about large amounts of vitamin C and antioxidant capacity.     

Development of the Maillard reaction in foods cooked by different techniques. Intake of Maillard-derived compounds

Specific and non-specific Maillard reaction (MR) indices such as CIELab colour, browning measurement, furosine, hydroxymethylfurfural (HMF) and furfural, as well as the nutrient content, were analysed for commonly consumed dishes, to test the effects of different culinary treatment on dishes composed of the same ingredients. In addition, the consumption of early MR products (MRP), Amadori compounds, HMF and furfural from a normal serving of these dishes was calculated. As expected, recipes including frying, apart from their particular composition, led to significantly higher values of furosine and HMF, ranging from 4.40 to 175 and from 0.30 to 22.7 mg/kg, respectively; consequently they provided the highest levels of Amadori compounds and HMF intake (0.42–26.8 and 0.02–2.38 mg/serving, respectively). Even so, MRP intake/serving was not very high in comparison with levels reported in the bibliography on some individual foods typically studied in terms of MR development, suggesting that the culinary treatments used do not make a great contribution to the daily MRP consumption.